The concept of psychosexual development, as envisioned by Sigmund Freud at the end of the nineteenth and the beginning of the twentieth century, is a central element in the theory of psychology. It consists of five separate phases: oral, anal, phallic, latency, and genital. In the development of his theories, Freud's main concern was with sexual desire, defined in terms of formative drives, instincts and appetites that result in the formation of an adult personality.

(People do not tend to fixate at this stage, but if they do, they tend
to be extremely sexually unfulfilled.)

Genital

Puberty and beyond

Sexual interest mature

Frigidity, impotence, unsatisfactory relationships

Oral phase

The oral stage in psychology is the term used by Sigmund Freud to describe the child's development during the first eighteen months of life, in which an infant's pleasure centers are in the mouth. This is the first of Freud's psychosexual stages.

This is the infant's first relationship with its mother; it is a nutritive one. The length of this stage depends on the society. In some societies it is common for a child to be nursed by its mother for several years, whereas in others the stage is much shorter. Suckling and eating, however, compose the earliest memories for infants in every society. This stage holds special importance because some, especially those in tribal societies commonly found in the Southwest Pacific and Africa, consider the stomach to be the seat of emotions.

Anal phase

The next stage of psychosexual development is centered around the rectum, but can also include bladder functions. This phase usually occurs from eighteen months to thirty-six months of age. In this stage children learn to control the expulsion of feces causing their libidinal energy to become focused in this area. The added awareness of this erogenous zone arises in children from concentrating on controlling their defecation. They come to see it as just another way to experience pleasure, and begin to take pride in either defecating in a fashion that may be considered socially unacceptable, or, in the case of very strict parents, they may begin to resist the urge to defecate to the extent where it becomes pathological. Two types of characters can develop out of this: the expulsive and the retentive. The expulsive character would have been prone to malicious excretion either just before they were placed on the toilet or just after they were removed from the toilet. The retentive character takes pleasure in holding in the feces in spite of his or her parents' training. The child comes to view the feces as a possession which he does not want to relinquish. Freud postulated that such children develop into adults who are usually neat, organized, careful, meticulous, and obstinate.

Phallic phase

At thirty-six months to about seventy-two months of age the libidinal energy shifts from the anal region to the genital region. At this point, according to Freud's model, the Oedipus or Electra complex can develop. The Oedipus complex is central to the psychodynamic fixations in this time period for men; the Electra complex for women.

Around this time in males, according to Freud, the young boy falls in love with his mother and wishes that his father was not in the way of his love. At this point he notices that women have no penis and fears that the punishment of his father for being in love with his wife is castration. This fear is enhanced if he is castigated for masturbation at this stage. Once the fear of retaliation has subsided the boy will learn to earn his mother's love by becoming as much like his father as possible. Thus, the superego is born. He will adopt his father's beliefs and ideals as his own and move on to the latency stage.

Freud's theory regarding the psychosexual dynamic present in female children in this point of their psychosexual development is termed, though not by Freud himself, the Electra complex. According to Freud, young girls, after they come to the realization that they have no penis, begin to blame the mother for having taken it, and look to the father as a substitute for the loss that they perceive. This is termed "penis envy." Freud's theory of feminine sexuality, particularly penis envy, has been sharply criticized in both gender and feminist theory.

Latency phase

The latency period begins sometime around the age of six and ends when puberty starts to begin. Freud believed that in this phase the Oedipus complex was dissolved and set free, resulting in a relatively conflict-free period of development. In this phase, the child begins to make connections to siblings, other children, and adults. This phase is typified by a solidifying of the habits that the child developed in the earlier stages.

Genital phase

The genital stage starts at puberty, allowing the child to develop opposite sex relationships with the libidinal energy again focused on the genital area. According to Freud, if any of the stages are fixated on, there is not enough libidinal energy for this stage to develop untroubled. To have a fully functional adulthood, the previous stages need to be fully resolved and there needs to be a balance between love and work.